With malt alcoholic beverages such as beer and low-malt beer which use barley malt as materials, using starch like rice, barley, wheat, corn starch as adjuncts other than malt, an activity enzyme of malt is used (for example, enzyme itself may be added to low-malt beer.), then malts or the starch of malts and adjuncts are made to mash, and after adding hops to an obtained a wort, then a brewers' yeast is added and an alcoholic fermentation is carried out.
On the other hand, unlike a malt alcoholic beverages, there is an alcoholic beverage that does not use brewing operation including process of steeping, germination and kilning, and process of liquefaction and mashing, that is, a beer-taste alcoholic beverage, which does not contain any malt or barley or wheat, etc. at all (alcoholic beverage by which a flavor is similar to beer) is disclosed. For alcoholic beverages, materials liquid is processed and created by adding a syrup containing sources of carbon, sources of nitrogen such as amino acid content material, water, hops, a coloring matter, an improving substance for a generation of foam and for the foam stability, and necessity spices, then the brewers' yeast is added to the materials liquid as same as usual beer brewing process, and the alcoholic fermentation is carried out. Nowadays, its development is progressing towards realization. (JP Publication number 2001-37462)
In these alcoholic beverages with foaming properties, there are important properties like the degree of foaming and the foam stability. For example, when beer is poured into a glass or beer mug, a form layer is created on a surface of the poured beer. This foam layer intercepts beer surface from air while impressing beer visually to a drink person, and it has the important function to confine a beer's taste. Therefore, moderate degree of foaming and the foam stability are properties indispensable to beer.
However, with conventional malt alcoholic beverages, since the degree of foaming and the foam stability as an alcoholic beverage of a final product are greatly affected by brewing process management of selection of malts' materials or adjuncts, a quality of malts, or a temperature control of the mashing process, thus an effort spent on these processing control has accounted for the remarkable ratio among all brewing processes.
Moreover, in an alcoholic beverage with foaming properties, any development of the improving material suitable for the generation of foaming and the foam stability is to be needed.
Although the improving material for the degree of foaming and the foam stability described above in the alcoholic beverage with foaming properties has been proposed to use as one method to improve the degree of foaming and the foam stability in alcoholic beverages with foaming properties, it has not been proposed concretely yet.